C++ remainder()

The remainder() function in C++ computes the floating point remainder of numerator/denominator (rounded to nearest).

remainder (x, y) = x - rquote * y

where rquote is the result of x/y, rounded towards the nearest integral value (with halfway cases rounded towards the even number).

remainder() prototype [As of C++ 11 standard]

double remainder(double x, double y);
float remainder(float x, float y);
long double remainder(long double x, long double y);
double remainder(Type1 x, Type2 y); // Additional overloads for other combinations of arithmetic types

The remainder() function takes two arguments and returns a value of type double, float or long double type.

This function is defined in <cmath> header file.

remainder() Parameters

• x - The value of numerator.
• y - The value of denominator.

remainder() Return value

The remainder() function returns the floating point remainder of x/y (rounded to nearest).

If the denominator y is zero, remainder() returns NaN (Not a Number).

Example 1: How remainder() works in C++?

#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    double x = 7.5, y = 2.1;
    double result = remainder(x, y);
    cout << "Remainder of " << x << "/" << y << " = " << result << endl;

    x = -17.50, y=2.0;
    result = remainder(x, y);
    cout << "Remainder of " << x << "/" << y << " = " << result << endl;
    
    y=0;
    result = remainder(x, y);
    cout << "Remainder of " << x << "/" << y << " = " << result << endl;
    
    return 0;
}

When you run the program, the output will be:

Remainder of 7.5/2.1 = -0.9
Remainder of -17.5/2 = 0.5
Remainder of -17.5/0 = -nan

Example 2: remainder() function for arguments of different types

#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    int x = 5;
    double y = 2.13, result;
    
    result = remainder(x, y);
    cout << "Remainder of " << x << "/" << y << " = " << result << endl;

    return 0;
}

When you run the program, the output will be:

Remainder of 5/2.13 = 0.74